For ex-Unicorns Nick Diamonds and Jaime Tambeu, releasing a "mature" follow up to their acclaimed 2003 debut could have been a total disaster. Considering that the Montreal group's unpredictable song structures and amateurish, lo-fi charm were what initially earned them so much praise, their decision to disband the Unicorns, start anew as Islands and release a comparatively traditional indie-pop record was certainly a gamble. However, Return to the Sea confirms that the gamble has more than paid off. Here, the duo in Islands has replaced its former band's spastic weirdness with an emphasis on traditional structure and arrangement that showcases the breezy sounds of calypso, synth-pop and rustic Americana. Opener "Swans" is an arresting standout track laced with bouncy pianos, and it immediately establishes the band's penchant for telling dark and cryptic tales over a musical paradox--light and pleasant sounds with surprisingly rich arrangements. In "Volcanoes," a ghost claims to know when the world will end against a background of sweeping strings and bright, jangling guitars, while "Don't Call Me Whitney, Bobby" is a cheerful discussion of decaying bones and skeletons accompanied by infectious rhythm guitar and a jumpy, danceable drum beat. Although Return to the Sea lacks some of the surprises of the Unicorns, its compelling and better-developed songs more than make up for it, cementing Diamonds' status as a great pop songwriter.